Research of the week
Early surgery for sciatica
N Engl J Med 2007; 356: 2,245-56
I am often frustrated with the long delays in patients with severe sciatica being seen and operated on when they have been referred with ongoing symptoms that severely affect their quality of life.
This study was somewhat reassuring, therefore. It involved assigning patients with sciatica that had not resolved within six weeks to either early surgery or to prolonged conservative treatment, with surgery if needed.
Their results showed that although more patients in the first group underwent surgery (88 per cent versus 39 per cent), there was actually no significant difference in disability scores during the first year.
The main difference reported was that those who had early surgery reported a faster relief of leg pain, although in both groups, the probability of perceived recovery after one year of follow-up was 95 per cent.
Mosquito nets and malaria
JAMA 2007; 297: 2,241 - 50
This week's edition of JAMA discusses various aspects of malaria, including one study that used national and international survey data from 1999 to 2006 to show that in sub-Saharan Africa, less than 7 per cent of households had an insecticide-treated net.
This is appalling, and a stark contrast to the target set by the WHO of 80 per cent of children and pregnant women sleeping under nets by 2010.
Although the actual nets are cheap (around £2 each) it has been estimated that it would cost around £112 million a year to reach the WHO target.
Folic acid supplementation and stroke
LANCET 2007; 369: 1,876-82
There still seems to be some confusion as to whether or not folic acid reduces cardiovascular disease by lowering homocysteine levels. This is a meta-analysis of trials to assess the efficacy of folic acid supplementation in the prevention of stroke.
Results showed that folic acid supplementation significantly reduced the risk of stroke, by 18 per cent; a greater beneficial effect was seen in those trials with a treatment duration of more than 36 months and in subjects with no history of stroke.
Should the HPV vaccine be introduced?
LANCET 2007; 369: 1,861-68
As cervical cancer is the second-most common cancer in women and kills 1,120 women each year in Britain, should we not be considering widespread use of the HPV vaccine here? This combined analysis of four clinical trials assessed the effect of prophylactic HPV vaccination.
Results showed the vaccine was extremely effective (99 per cent efficacy) in women aged 16-26 who were negative for HPV16 or HPV18 infection during the vaccination regimen. There appears to be benefit in vaccination programmes for countries with high rates of cervical cancer and no screening but it is still unclear whether vaccination in countries with effective screening would have a similar result.
Ultrasound for children with simple UTI
ARCH DIS CHILDHOOD 2007; 92: 502-4.
The practice of renal ultrasound for young children after a first UTI was questioned in this observational study.
Children under five who were hospitalised for a first simple UTI had their ultrasound results compared with their prenatal ultrasound. Complete concordance between the two was shown in 96 per cent of cases.
The authors argue that because antenatal ultrasounds of the renal tract are performed in most children, those with normal prenatal scan results do not need to have an ultrasound when they present with a first simple UTI. It remains to be seen whether other experts will agree.
False positive HIV tests with rapid testing
BMJ doi:10.1136/bmj.39210.582801.BE (online)
Rapid tests for the detection of antibodies to HIV-1 that do not require laboratory facilities are highly valuable, especially in the developing world. However, this study has demonstrated that use of these tests can lead to false positive results.
Men from Uganda were screened for HIV using three rapid tests and the results compared with those of enzyme immunoassay and Western blotting (the optimal methods).
Although the sensitivity of the rapid tests was high (97.7 per cent) they had a low specificity (94.1 per cent) and a low positive predictive value (74 per cent). The authors concluded that weak positive bands on the rapid tests should be confirmed by the optimal methods of diagnosis.
Dr Newson is a GP in the West Midlands, and a member of our team of GP research reviewers
The quick study
Mosquito nets, although inexpensive, are not widely used enough to prevent malaria in sub-Saharan Africa.
Folic acid supplementation reduces the risk of stroke by 18 per cent.
HPV vaccination appears effective against HPV16 and 18 in women aged 16-26.
Ultrasound after first UTI may be unnecessary in children with a normal antenatal ultrasound.
Rapid HIV tests may need confirming if the result is a weak positive band.